Paul
Paul

Reputation: 6176

Get the frame of UIBarButtonItem in Swift?

how could I get the frame of a rightbarbuttonItem in swift? I found this : UIBarButtonItem: How can I find its frame? but it says cannot convert NSString to UIView, or cannot convert NSString to String :

let str : NSString = "view" //or type String
let theView : UIView = self.navigationItem.rightBarButtonItem!.valueForKey("view")//or 'str'

The goal is to remove the rightBarButtonItem, add an imageView instead, and move it with a fadeOut effect.

Thanks

Upvotes: 20

Views: 24392

Answers (3)

Dan Stenmark
Dan Stenmark

Reputation: 601

import UIKit

class ViewController: UIViewController {

    let customButton = UIButton(type: .system)

    override func viewDidLoad() {
        super.viewDidLoad()

        customButton.setImage(UIImage(named: "myImage"), for: .normal)
        self.navigationItem.rightBarButtonItem = UIBarButtonItem(customView: customButton)
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        print(self.customButton.convert(self.customButton.frame, to: nil))
    }
}

You must use UIBarButtonItem objects created with customView for this; UIBarButtonItem objects created the regular way don't have enough information exposed. It's important that the frame be looked up after the parent UINavigationController's UINavigationBar has completely laid out its entire subview tree. For most use cases, the visible UIViewController's viewDidAppear is a good enough approximation of this.

Upvotes: 4

ePing Tu
ePing Tu

Reputation: 51

In Swift4, XCode9

    for view in (self.navigationController?.navigationBar.subviews)! {
        if let findClass = NSClassFromString("_UINavigationBarContentView") {
            if view.isKind(of: findClass) {
                if let barView = self.navigationItem.rightBarButtonItem?.value(forKey: "view") as? UIView {
                    let barFrame = barView.frame
                    let rect = barView.convert(barFrame, to: view)
                }
            }
        }
    }

Upvotes: 5

Christian
Christian

Reputation: 22343

You should try it like:

var barButtonItem = self.navigationItem.rightBarButtonItem!
var buttonItemView = barButtonItem.valueForKey("view")

var buttonItemSize = buttonItemView?.size

Edit (Swift 3):

var barButtonItem = self.navigationItem.rightBarButtonItem!
let buttonItemView = barButtonItem.value(forKey: "view") as? UIView
var buttonItemSize = buttonItemView?.size

Upvotes: 39

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